摘要:

A semi‐analytic form for the axial buckling force of a multistage vibration‐isolation stack for gravitational radiation detectors is deduced. This is another version of Euler’s formula for simple pillars and gives a reference value both in design of isolation stacks and in numerical analysis for more complicated situations.

ISSN:0034-6748    

DOI:10.1063/1.1145107

出版商:AIP    

年代:1994

数据来源: AIP

摘要:

Described is the design for a new electrochemical cell forinsitustudies with the atomic force microscope. Improvements over presently used cells include an axially symmetric electrode geometry, large counter electrode, and the ability to incorporate a standard reference electrode close to the working electrode.

ISSN:0034-6748    

DOI:10.1063/1.1145108

出版商:AIP    

年代:1994

数据来源: AIP

摘要:

A new miniature interferometer has recently been developed for monitoring the changes of film thickness and refractive index, wherein a semiconductor laser and a photodiode detector are integrated to form a laser/detector hybrid. The laser light is collimated by a lens. When the laser light hits a film, it is reflected twice by the two interfaces between the film and the surrounding mediums. The two reflected light beams are interfered at the detector by the same lens. Due to the interference, the detected intensity is a function of the film thickness. The swelling of thin gelatin gel film has been used to demonstrate the use of this novel sensor. The sensor is ready to be used in many applications, such as inside a vacuum chamber, on a robot arm, and in a small reaction container, wherever a conventional interferometric setup cannot be easily implemented because of its size.

ISSN:0034-6748    

DOI:10.1063/1.1145109

出版商:AIP    

年代:1994

数据来源: AIP

摘要:

An improved method is reported for measurements ofI‐Vcharacteristics of high‐Tcsuperconductors based upon the acquisition system developed by Kirkupetal. [Rev. Sci. Instrum.63, 2044 (1992)]. The introduction of a lock‐in mode of operation significantly enhances the voltage sensitivity in the range of relevance for the definition of the superconducting state. In addition, this approach permits the current direction in the sample to be reversed whenever needed.

ISSN:0034-6748    

DOI:10.1063/1.1145110

出版商:AIP    

年代:1994

数据来源: AIP

摘要:

A review of Penning ionization gauge (PIG), duoplasmatron (DP), laser‐plasma ion source (LPIS), Electron cyclotron resonance ion source (ECRIS), and electron beam ion source (EBIS) used for the production of intense and high charge state ion beams is given. The outputs of high charge states of different elements of the Periodic Table from ion sources of these types are compared. Bare nuclei up to Ar can be obtained from EBIS and ECR and Xe+54from EBIS. Comparisons are made of compilations of the output (high average current of 107–1017pps) for different charge states of Xe for PIG, DP, ECRIS, EBIS ion sources and Ta, Pb for different charge states of the LPIS. The present level and perspectives of development (a pulsed gas feed, stationary electric field) of the PIG ion source are presented. The beam performance and future development of these intense and high charge state ion sources are discussed from the point of view of the perspectives of the cyclotron programs at FLNR and JINR.

ISSN:0034-6748    

DOI:10.1063/1.1145111

出版商:AIP    

年代:1994

数据来源: AIP

摘要:

At the Workshop, the operation of various new and existing ECR ion sources was reported, with most of the emphasis on new methods to improve the performance and extend the variety of species. Much attention was paid to theoretical aspects, in particular to the basic question of electron heating; a complete investigation is still considered to be a long term project. A number of measurements of diagnostic character were presented. The strong radial component of the field in the magnetic trap turns out to play a crucial role in the confinement of hot electrons and hence in the production of very high charge state ion beams. A donor for cold electrons in any form—like a biased probe, plasma cathode, or electron gun—contributes strongly to increased output and stability of operation of the ECR ion source.

ISSN:0034-6748    

DOI:10.1063/1.1145112

出版商:AIP    

年代:1994

数据来源: AIP

摘要:

This article gives a short summary of the performances of the electron cyclotron resonance ion sources (ECRIS) so far built by the Grenoble laboratory; emphasis is given to the highBfield Caprice source, a compact in size source delivering high charge states and high intensities. Both the continuous regime of operation, and the pulsed regime having performances enhanced by the afterglow effect, as well as other noticeable effects, are surveyed. The next part of the article deals with the analysis of the data and our present understanding of the ECRIS behavior. At last the present trends of development of ECRIS are examined.

ISSN:0034-6748    

DOI:10.1063/1.1145113

出版商:AIP    

年代:1994

数据来源: AIP

摘要:

The project for a superconducting electron cyclotron resonance (ECR) ion source has been funded by INFN in 1992 as a joint venture between INFN and CEA/DRFMC. The source is devoted to the production of high charge state heavy ions to be injected into the K‐800 superconducting cyclotron. The magnetic system consists of three solenoids and of an hexapole which will allow one to attain a strong plasma confinement by means of aB‐min field configuration with a very high magnetic field (1.4 T on the plasma chamber wall). At the intermediate frequency of 14.5 GHz, it will be possible to study the scaling of ECR ion sources at different magnetic fields far beyond the existing levels. The source will eventually work at a higher frequency, in the range 28–35 GHz of gyrotron tubes. The design of the superconducting magnets and of the cryostat has been carefully carried out, taking into account this goal, and the construction is now under course. The mechanical design of the plasma chamber is also outlined.

ISSN:0034-6748    

DOI:10.1063/1.1145060

出版商:AIP    

年代:1994

数据来源: AIP

摘要:

We would like to present the initial results and description of the superconducting electron cyclotron resonance ion source (SCECR) operating in the high‐Bmode—a new high magnetic field, low‐frequency mode of operation. First, we describe the operating characteristics of this mode, which include very high mirror confinement in all directions, yet having a minimum field low enough for electron cyclotron resonance heating of 6.4 GHz. The source performance for oxygen, neon, argon, krypton, and xenon is presented and comparisons are made with several existing high‐performance ECR sources. In this high‐Bmode the SCECR matches or exceeds the performance of all existing ECR sources. These results perhaps invalidate the classical frequency squared source performance scaling law, and suggest the new possibility of high‐performance, low‐frequency (and hence low cost) sources as will be discussed.

ISSN:0034-6748    

DOI:10.1063/1.1145061

出版商:AIP    

年代:1994

数据来源: AIP

摘要:

The main goal of this project was to increase the reliability of CRYSIS by separating the ionization region from the insulating volume which contains vacuum seals at the cryostat. These volumes are separated with two bellow units installed between the cryostat and both ends of the vacuum vessel. The bellow units contain drift tubes with different fixed temperatures, heat shields, feedthroughs for drift tubes, and a gas delivery tube for gas injection. Preliminary results of tests after CRYSIS vacuum separation are presented.

ISSN:0034-6748    

DOI:10.1063/1.1145062

出版商:AIP    

年代:1994

数据来源: AIP